Automatic step-speed power transmission



Sept- 28, 1954 c. H. RICHARDS 2,690,247

AUTOMATIC STEP-SPEED POWER TRANSMISSION Filed June so, 71948 s Sheets-Sheet 1 INVENTOR.

Sept. 28, 1954 C. H. RICHARDS AUTOMATIC STEP-SPEED POWER TRANSMISSION Filed June 30. 1948 6 SheetsShet 2 uvmvrm WWMQ.

Sept. 28, 1954 c. H. RICHARDS AUTOMATIC STEP-SPEED POWER TRANSMISSION 6 Sheets-Sheet 3 Filed June 30. 1948 Sept. 28, 1954 c. H. RICHARDS AUTOMATIC STEP-SPEED POWER TRANSMISSIONN Filed June 30. 1948 6 Sheets-Sheet 4 INVENTOR.

Sept. 28, 1954 c. H. RICHARDS 2,690,247

AUTOMATIC STEP-SPEED POWER TRANSMISSION Filed June so, 1948 a Sheets-Sheet 5 mediate Patented Sept. 28, 1954 UNITED f STAiT'ES. :FATE'NT OFF-ICE AUTOMATIC STEP-SPEED POWER TRANSMISSION CarrollH. RichardaBoston, Mass. Application June 30, 1948, Serial No. 36,034

.15 Claims.

This invention relates to -=.new improvements in automatic step-speed power-transmissions and particularly torthattype;ofztransmission that is both torque controlled .and contro1led ':;by the speed of the final driven element. Such a trans .-m-ission:is:'disc10sed in applicants Patent No.

Theparamount. objects of this'invention are the simplifications of: construction; the eliminating of al1' friction .:controls :and the eliminating of I the main clutch which :heretofore was 1 requisite in the performance of these transmissions.

.What is meant'here byeliminating xthe main clutch isthat:xtheshiftingrmechanism rfor the low :speed'functions 'bothaas' anautomatic clutch and a shifting mechanism.

'In; this application the mechanism to simplify 'the construction is dominated Pby :applicants Patent No. 2,407j099i8.nd pend-ingaapplication for patent 'Serial No. -"6'Z1%,'B89, zfiled May "20, 1946, :now' Patent No. 923544.107, dated March 56, 1951. EFOI' 'the .purpose :of facilitating the-description =-of the. construction :and performance of this in- .ventin,--formsof construction of the 'Patent' No. 2,407.;699 and pending application for patent Sea.

rial No. -671;0,89':are disclosed in the drawings' and described --in this-specification.

:In. theaccompa-nyingdrawings:

Fig. 1 .is a=longitudinal section-:of :a :two-way overriding device, .with some parts shown in elevation,1in:which all-spur gears or helical gears i of :a small;helicaleangle may be employed.

'jFig. 2 is asectionstaken along line 22 I in" Fig. 1. Fig. '3 is :a section taken along 'li-ne 3-3 in Fig. 1.

Fig. 4 is a:diagra1nmatic-view for the purpose of; explaining theperformance of thedevice.

:Fig..5;is. -an' elevation of an automatic device centrifugally. controlled.

Fig. 6 is a'ilongitud-inal section-of the device :shown ini;Fig.-.r5, with some parts in-elevation.

Fig.1? is aniend view-of-the:deviceshown in Figs. '5 -an'd' 6 :when the device is centrifugally controlled.

i-Fign'8=is;an.-end :view of'the device shown in 'FigSJ25 and 56 when the clevice is controlled by spring. tension.- only.

;F ig. 9 =is a detail :of :the spring tension control mechanismuwith partstbrokenxaway.

Fig. 10 isan end: view: of-,anintermediate; speed I shifting mee-han-ism :entirely torque controlled,

.with some; parts shown broken away and ,in a

non-drivingmosition.

Fig. 11 is alonsitudinal-seotion :oican interspeed shifting mechanism entirely 2 torque'controlled withsome parts shown in elevation, some parts broken-away and ma nondriving position.

Fig. 12 is a sectional view taken -along-line HZ-l2 in Fig-ll.

Fig. '13 is an end view of an intermediate-speed shifting mechanism controlled by torque-and by centrifugal force, with-some parts hrokenaway "and shown in a non-driving position.

Fig. 14 is a side elevation of an intermediate speed shifting mechanism controlled by "torque and centrifugal force, with some parts broken away and shown in a non-drivingposition.

Fig. 15 is a similar-view to Fig.-12: and shows "the relative positions of the parts when the mechanism is in a driving position, particularly as regards the gears and'this applies to both entirely torque controlled and torque controlled and centrifugally controlled mechanisms.

Fig. ls is a similar view'to-Fig. l2 'and'shows therelative positions of the parts when the mechanisrn'is in hold-back posit-ion, particularly as regards the gears and this applies :to both-entirely torque controlled and torque controlled and centrifugally controlled mechanisms.

Fig. 17 is an end view of a high speed shifting mechanism, both torque and centrifugallycontrolled with the floating shaftin section.

-Fig.'18 isa side View of a high speed shifting mechanism, both torque and centrifugally controlled with some parts in elevationand some parts in section.

Fig. 19 is asectional View along line 19-!9 in Fig. 18.

Fig. 20 is a sectional view along line '20'2fl in 'Fig.'1$.

Fig. 21 is a sectional view'along line 2I2l in'Fig.'18.

shifting mechanism and automatic clutch-taken along linen-2t in Fig. 22.

Fig. 25 is a longitudinal section of a stepspeed automatic power transmission showing a high speed shifting mechanism and an inter- 3 mediate speed mechanism, both torque and centrifugally controlled with some parts in section and some parts in elevation.

Referring to the drawings Fig. l discloses a two-way overriding device in which A is the driving shaft and D is the driven shaft. Driving shaft A is journaled in ball bearing 2? conventionally held in housing 28 part of which is broken away and driven shaft D is journaled in ball bearing 29 conventionally held in housing 36 part of which is broken away. An eccentric B is integral with driving shaft A. Driving shaft A has two portions 3i and 32 of different diameters, portion 32 has the smaller diameter and is journaled in ball bearing 33 conventionally held in receptacle 3d of gear C which is integral with driven shaft D. A shoulder 34 formed by the portions 3! and 32 of driving shaft A, which have different diameters, abuts the inner ring of ball bearing 33. The end of hub 35 of gear C abuts the inner ring of ball bearing 29.

A member E fits over the cylindrical surface of eccentric B and is free to turn over this cylindrical surface. A lip 36 of member E projects inwardly and the inner surface of lip 3E movably abuts one side of the eccentric B and the outer surface of said lip inovably abuts the inner end surface of spacer collar 3?. Spacer collar 3'! is free to rotate on driving shaft A and its outer end abuts the inner ring of ball hearing 21.

Shafts 38 and 39 have heads M2 at one end and are threaded at the other end. They each have two different diameters and the portions having the smaller diameters fit tightly into holes 4! and 42 in member E and part of their larger portions fit into counterbores 43 and 44 of holes ll and 42 respectively. Shoulders formed by the portions of the different diameters are drawn tight against the bottoms of the counterbores 43 and M by tightening nuts 45 threaded on the ends of said shafts 33 and 33. Conventional lock washers under the nuts press against one side of member E and prevent the nuts from turning after they are tightened. Keys and key ways lli prevent shafts 38 and 39 from turning in holes (ii and 12 of member E.

Bushings t! fit tightly into gears G which are mounted on and free to rotate about the large portions of shafts 38 and One side of flange portions 43 of bushings i'l movably abut the ends of bosses d9 of member E and the other side of flange portions it fit tightly against one of the sides of the gears G. Washers d fit into counterbores 5! of the gears G and the outer fiat surfaces of washers 5i! movably abut the inner flat surfaces of heads as of shafts 33 and as. Gears G mesh with gear C and only one of the gears G takes the load, the other gear functions only as a counterbalancing weight, which will be more fully explained in the description of the performance of this mechanism.

If the driving shaft A be rotated in either direction of rotation, and the driven shaft D be at rest, eccentric B integral with shaft A will cause member E to be pulled downward as viewing Fig. 1. This movement of member E will pull the top gear G downward and either the top of a tooth of gear G will contact the bottom of a tooth space of gear 0 or a top of a tooth of gear C will contact the bottom of a tooth space of gear G depending on the relative positions of the gears (3- and C at the time the rotation of shaft A started. This movement of member E would cause the top of a tooth of gear G to contact the bottom of a tooth space of gear (3' if the relative positions of gears G and C were 2. shown in the drawings. If the rotation. of driving shaft A continues after the top of a tooth of one of the gears G or C has contacted the bottom of a tooth space of one of the gears G or C, gear C and gear G will be locked together and gear C which is integral with driven shaft D will rotate at the same speed as driving shaft A, or in other words the entire mechanism will rotate bodily. It is obvious that the greater the driving torque of driving shaft A and the greater the resistance oifered by driven shaft D- in direct proportion the greater the pressure of a top of a tooth of one of said gears on the bottom of a tooth space of the other of said gears. it will also be noted that when one of said gears G is moved toward the common axis of rotation of the driving and driven shaft A and D respectively, that the other of said gears G is moved outwardly and away from this said common axis of rotation, carries no load and only functions as a counterbalancing member a counterbalancing member other than a gear could replace it. Since it is intended to employ spur or helical gears of a small helical angle in this construction the center of rotation of member E must be spaced (as defined in applicants Patent No. 2,407,099) close to the common axis of rotation of the driving and driven shafts A and D respectively, and to secure strength and inexpensive construction when the offset center is close to the common center of rotation, the conventional eccentric is employed which has been the solution to problems of this nature since practically the birth of mechanisms.

In Fig. 4- the angle m is equivalent to substantially the travel of one tooth and tooth space of the gears shown in the drawings. distance r is substantially the distance this angular travel m of the eccentric B would pull the gear G toward the common axis of rotation of the driving and driven shafts A and D respectively. It is obvious that this distance a: is much greater than the distance required to cause a locking of gears and it follows that the gears can be locked in a much less travel than that of one tooth.

If the driven shaft D be rotated in either direction of rotation and the driving shaft A be at rest, gear C, integral with driven shaft D, meshes with gears G and gears G will be rotated in the opposits direction to the direction of rotation of gear C. Due to this rotation just described, gears G will be forced outward away from the common axis of rotation of the driving and driven shafts A and D and this outward movement depends on the pressure angle of the gears, the greater the pressure angle the greater the force, to force the gears apart. So if driven shaft D rotates gear (I in either direction of rotation there will be no appreciable drive transmitted through gears G, member E and eccentric B to driving shaft A.

So it follows if driving shaft A rotates faster in either direction of rotation than driven shaft D is rotating, that there will be a lockup of the gearing and driven shaft D will rotate at the same speed as driving shaft A. But if driven shaft D rotates faster in either direction of rotation than driving shaft A, it can continue rotating faster in either direction of rotation, gears G will idle about their shafts and 39 and there will be no appreciable driving force transmitted by driven shaft D and gear C through gears G, member E and eccentric B to driving shaft A.

Referring to the drawings, Figs. 5, 6, '7, B and 9 I mesons? :disclose two designsef automatic devices controlled by the speed df one of its elem'ents; one :by spring -tension alone and the other by" centrifugal iforceo'f revolving weights working against spring tension and these unechariismssare claimed :inzap- 1151102111338 :pendingapplication SerialiNo. 65.11089, f'filed Mayii20, 1-9746. DrivingshaitsN isijournaled ;in indicated bearing 52 rand-:driven :shaft; D .1 is .ijournale'd tin indicated :hearing 53. A fdisc LEA is integralwith driving shaftxA andhuzbstfiS zazn'dififi ;are' integral with the :disc 54. l'Iihez'outer rend rof .lhlib 5Ermovablyaabuts"indicatedabearing 52. .Hub :56 (has a ."receptacle 15:! "in which is conventionally meld balhbearingifill.

Driven :s'haft D at :its inner :end :has .:two::pnr- Ltions of different :diamet'ers T19 sand zfilljtthersmaller :of the two is journaled'in ball "bearing :58rhe'1d tin receptacle 25:1 :in 'the hub '56. "The shoulder :formed by the difference diameters offlieiporitionsr59 and {it :of :driven shaft *D abuts "the inner ring ofrball bearing 5:8.

Spur gear is integral *with drivenwshait D andi'has aJhub 6 l 'thezouterxend :of -whiclnmov-ably abuts the indicatedbearingzSS. "Helical gearsfi mesh with spur gear C arewmountedionzand'are free-to rotateahout fixed shafts :62, =whicl'iifitlinto holes 63 in bifurcations 64 :of members dj sand located and :prevented from turningin holes -53 :by tapered "pins 6-5 which pierce the ibifurca'tions .fitandoneof'the ends ofthe shafts :62. :Members E are freeto turn about fixed shafts lifi which-fit =into'-'zholes:-fi 'i and (63 of membiers-E :and (have heads 69 at one of their iEIldS, the inner surfaces :of heads 69 movably za-but a surface of members .E -(see:Eig. 6).

gitudinally .and prevented from turning :bYn'llWO 'balls 10, one set of these-balls fit partially in holes H in the shafts 6.6 :and partially :into :slots 12 circular in form in the-.disc 54 (-see.-Fig. '7') The other set of r ballsfit'entirely inholes H contact the-other-set of :balls :and apinsal3. P.ins:l 3 are a ,plain surface portion of rscrews 11-4 and fiti'nto holes 15 in the center .ofhshafts-tfi. Screws 1 4 :are threaded inholes in :the center oft-fixedzshaftssfiii and conventional lock washers 2arelocated under the heads .ofscrews Hand contact the-outer-.-su-rface of the :heads 89' of :fixedshafts :65 and prevent the screws 14 .from turning-when they-are tightened .in their ithreads.

Members E straddle the diSc==54:ln.-n013(lheS 16 and have inner cylindrical surfaces 1-! .which aare adapted to turn over cylindrical surtaces-lll -.of

the disc 55, which are tor-med .in the notches -16. Inner surfaces 18 .of members E qaccurately-i-fit lmovably on raisedrsurtaces 189 of the 411 so :54.

Pins 'BI vare threaded in .disc54 and :the bosses .82, are keyedin the-disctld keys and keywaysare .not shown), to ,prevent the pins .8 i i from turning (see Figs. 5 "and 7 and .areadapted .to .fit into holes 83 in weights W. The facesnf bosses ,84of the weights Wimovabl'y 'fitontothe facesiof bosses 82 of the .disc154 and theweights-W areiree to rotate about the ,pins. 81. .Springrings 185-.are movably contacted on one of their 'sides Lbythe faces of bosses '85 of the weights W,'fitinto grooves of the pins 8| and locate andfhdldlthe weightsW on pin 8! a .Aperturesril 'l "in discffi l house springs K, .one of 'the ends of springs 3K are'tfa'stened'todisdid near its hub 55 by the ends of said springs having hooks which fit into holes in the disc E l andf'holes in washers 88 (see 'Fig."7). The "other ends of springs "K are hooked through holes in pins ."89 which movably fit into holesin'the weights W and have heads -on their ends "oppositethe ends to "Whic'hthe springs K are fastene'd. 'The'springs K Fixed @shafts tfisare located lOIl- 6 ibe'ingfasteneditooneiendrofzpinsifill anditheiheails ao'fatheirsother locate find=71fl0ld1llh6 pinsr89 fiweig htaw. 56am surfaces .90 (of weights a'contact the :inner :surfaces of arms :91 ."iinteglal :wardly, the cam surfaces ;90 move away .from :the winner surfaces .of :arms :9 I of members E rand the :members' 1E will "be ;permitted to. rotate a about :the

":fixed shafts t6 until "the ;predetermined :limit :of

this counterclockwise rotation :issreached.

--In the above description the control of the movement of :members E -tabout :the fixedshaft 66 :by weights and springs :has :heen described.

The following is-a description of the control :0f

@the .imovement'of :the :members :E about their afixed shalft'fifi hysp i l The design-of :the automatic device disclosed in Figs. 28 and 9 :iS exactly :the zsame in construction as the device construction shown in vE'igs. 5 and 6 which has been described, exceptthatsprings-R replace bo1th the weights 1and-springs K .(seerFig. r8)

Inflig. 28- lugs 9.2 emit-33 a'redntegral withtthe disc-:54. Rods H havetwo different diameters :and two slots at right angles-to each :other 394 :and 94' at the-ends'oithe said i-rods having the larger -:diam'eters. Thealarger rdiameteruportions :Of rods EHzfit slidably intozholes 95zin=lugsi92 and lithe smaller 'diameteruportions of -rods Hzflt :slid- .zably (in holes BGdmIug-s 93. Washers 9=1fit tightly non theasmaller zportionzof rods 1H and tightly up .:against xtheashoulders formed :by the :said two dif- :ferent diameters of itherods .H. Springs :Rmress :against the inside surfaces ;of llugs 293 and :against the "inside l-surfacessof washers :9?! :and encircle the small diameter portions -of the rods H. The

ioutsideidiameters of awashers 19:1: -being largerthan holes -=S5 :influgs 192, enable :spring's -R tc .hold

washers 97 tightly againstvt-heinside-surfaces of ;;lugs \92. Rollers 293 have :heads on each :of their tends, :fit :into slots M 0f .thesrods :H andrare :locateid 'longitudmally in-rslots M by the :headsaat .each efatheir:ends. Arms 91- integral .wlithimem 0 hers :E 1 fit into :slots '94 0f :rods .Hrcontact "rollers :98 anddtis obviousathatrmenibers E (cannot rotate rabouttheir :fixed shafts rfifi :in a :counterclockwise -fdirection as viewing Fig. 8 a without compressing springszR.

To :describe-xthe :performance 0f the automatic device shown. :Figs. 25,16 and L7, assume the drive -=shaft;h is rotating inia -:clockwise-direction :as

viewing Lwthatrthe speedds-"n'ot zsuificient to wcause the weightsW :due to "centrifugal force to .start to move outwardly away from their inner- "most pDSition .and that driven :shaft :Dkaand spur gear 0 integral with shaft.-D are .at rest. Disc he integral with driving shaft A will .rotatewvith shaft 'A end-.carrylmembers :Ehwith it. :Helical gears --G .oarried in rtheibifiurcations 6d of memaround :gear 1C and there will be no appreciable driving iforce imparted :to gear C lou't there will he a tendencyifor members E to turn-about their -iixed shaft- 66 in a counterclockwise direction as viewir g "Fig. "Zfibut this is 'prevented by arm 91 contacting cam surfaces "of'the weights .W. Assuming now the speed of the driving 'shaft A is gradually increased, the weights W start to move outwardly and the gears G idle faster, the cam surfaces 90 move away from the inner surfaces of arms 9|, permitting the members E1 to move in a counterclockwise direction as viewed in Fig. '7 due to the faster idling of gears G and their tilted positions and a certain amount of driving force is transmitted to the gear C and the driven shaft D which is integral with gear C This part of the performance is analogous to the performance of a slip-ping device and automatically secures smooth starting. As the speed of the driving shaft A continues to increase the weights W move farther outwardly, the members E turn farther in a counterclockwise direction, the slipping device performance continues and the driving force imparted by gears G to driven gear C increases with the speed of driving shaft A This slipping device performance continues until the speed of the driving shaft A has increased to cause the weights W to have travelled to a point that has caused the cam surfaces 89 to be just out of contact with the inner surfaces of arms 9| at which time the members E1 have turned in a counterclockwise direction as viewing Fig. 7 so that the tops of the teeth of one or the other of gears G or C have contacted the bottom of the tooth spaces of the other, the device is engaged and the driven shaft D must rotate at the same speed as the driving shaft A By inspection of the drawings it will be seen that if the driven shaft D should attempt to rotate faster in the same direction of rotation than driving shaft A is rotating after the device is fully engaged as *just described, the device will remain engaged since the tendency would be to cause the members E to rotate in a counterclockwise direction. But if either the driving shaft A or the driven shaft D should start to rotate in a counterclockwise direction as viewing Fig. 7 faster than the other, the members E would turn in a clockwise direction as viewing Fig. 7 and there would be nothing to prevent a complete engagement by the tops of the teeth of one of said gears contacting the bottoms of the tooth spaces of the other.

To describe the performance of the automatic clutch shown in Figs. 5, 6 and 8 assume that the driving shaft A rotates in a clockwise direction as viewing Fig. 8 and gradually increases in speed. When the speed is at a predetermined low speed the resistance of the springs R will be such that they will not be appreciably compressed by pressure of the arms ill on the rollers 98, caused by the helical gears G idling as they are carried about driven gear C which causes or tends to cause members E to rotate in a counterclockwise direction as viewing Fig. 7. But as the speed of the driving shaft A increases this idling of gears G and their tilted positions permitted as the springs R are compressed, cause the springs R to be compressed more and more as the speed increases by causing the members E to rotate farther counterclockwise. This motion is transmitted through arms 9| to rollers as, to rods H and then to the springs R. As these springs R are compressed as the speed increases the slipping performance as described in the foregoing continues, until the rotations of members E rotate counterclockwise, as viewing Fig. 8, to a point where the tops of the teeth of gears G or gear C contacts the bottoms of the tooth spaces of the other and complete engagement of the parts is established and remain established as long as the speed necessary to cause the engage- (a ment is maintained or increases. The performance of this design of automatic device other than that performance just described is exactly the same as the performance of the first described design of the automatic device.

The foregoing description of the construction and performance of devices contributes to a better understanding of the description of the constructions and performances of the shifting mechanisms that follows. Parts of the shifting mechanisms that function the same as parts of the devices have the same basic reference char acters as nearly as possible. Referring to the drawings, Figs. 10, 11 and 12 disclose a torque controlled shifting mechanism in which A is a hollow driving shaft and D is the driven shaft. Bearings are not shown for the driven shaft D as this mechanism would be located in the midportion of a step-speed power transmission and the shaft designated as driven shaft D would be the floating shaft journaled near each end of the transmission. All driven shafts of the shifting mechanism shown and described as isolated units in this specification are referred to and considered in this manner.

A gear 99, which would receive the driving power from a gear on the countershaft of a transmission, is keyed to hollow driving shaft A by key and keyways Hit, and is mounted on driven shaft D and free to rotate about the said shaft on needle bearings Hill entailing the usual conventional construction. Conventional split ring I02 fits on driven shaft D into counterbore Hi3 of gear 99, abuts the ends of splines lu l on the driven shaft D and movably abuts the bottom of counterbore I03 and the end of hollow driving shaft A The other end of hollow shaft A movably abuts the face of boss H I of member E Gear C is integral with driving shaft A and meshes with gear G mounted on fixed shaft Hi5 integral with member E and is free to rotate about fixed shaft I05 on needle bearing lee en tailing the usual conventional construction. A collar I0! fits on the outer end of fixed shaft I05 and is held in place by tapered pin me which pierces both the fixed shaft and collar. One end of gear G movably abuts the inside surface of collar [0! and the other end of gear G movably abuts the face of boss i d9 of the member E Member E is mounted on and free to rotate about eccentric B Eccentric B is loosely splined on driven shaft D and has a limited movement in either direction of rotation without establishing a driving connection between the eccentric B and the shaft D (see Fig. 10). The reason for this limited movement is to facilitate the establishing of a driving connection between the driving shaft A and driven shaft D more fully explained in the description of the performance of the mechanism.

Counterbalancing weight H2 and arms H3 are integral with member E A plain portion of driven shaft D loosely pierces hole H4 in member E and one end of eccentric B movably abuts the face of a boss which is integral with member E and is shown in broken lines and encircles hole I M. The other end of eccentric B abuts the inner end of collar l i 5 splined to driven shaft D in splines llfl. Arms H6 are integral with collar H5.

Springs R under predetermined compression, have their seats in recesses ill and H8 in arms H3 and H6 of member E and collar H5 respectively. This terminates the description of the construction of an entirely torqued controlled speed shifting mechanism. Theouter end of collar- I I5 would abut normally asplitring similar to split ring I02 with the usualconventional construction. These two sp rings w uld lo ate t e shifting mechanism on the driven shaft D longitudinally. In a step-speed power transmission construction, driven shaft D would be the floating shaft of the transmission which will be more fully explained in the part of this specification that follows. This speed shifting mechanism just above described would be particularly adapted for the intermediate speeds of a step-speed power transmission.

The following is a description of an intermediate or low-speed shifting mechanism both torque and centrifugally controlled (seeFigs. l3 and 14). A collar H5 is splined to shaft D in splines H and arms H6 are integral with collar H. Weight W replaces counterbalancing weight H2 described in the foregoing, and is adapted to move toward and away from the common axisof rotation of the driving shaft A and driven shaft D and this movement is controlled by springs K and the centrifugal force acting on the weight W when the said weight is revolved about the said common axis of rotation.

Rods H9 have feet I20 partially circular in form integral with the rods and the circular portions are larger than the rods. Two slots I2I and I22 in each side of the weight W are adapted to receive the rods H9 and feet I20 respectively and rods H9 are attached to weight W in this manner. Rods H9 slidably fit into holes I23 in arms H 6. Springs K encircle rods I Ill and have seats on the inner surfaces of arm I I6.

A yoke I has lugs I24 integral with it inwhich are holes I25. The inner surfaces of lugs I24 form seats for springs K and the ends of rods H9 fit tightly into holes I25. Conventional spring ring and groove constructions I26 on the ends. of rods H9 hold the lugs I24 on the said rods and theseats of springs K on lugs I24 are held tightly against the springs K which are under a predetermined compression. Guide rods I21 are threaded in weight W andarefurther secured to weight W by set screws I28 threaded in holes in thesides of weight W andpartially pierce guiderods' I21. Guide rods I21 fit slidably into holes I 23 of the arms HE.

A hub I30 of member E has notches I3I whose sides are sloping and slope inwardly toward each other. The narrow ends of these notches I3I are adapted to. register with the sides of slots I32 rectangular in section and cut in the eccentric B Notches I3I of the hub I30 are diametrically .opposite each other and the slots I32 of the eccentric B are also diametrically opposite each other. Projectionv I33 integralwith the yoke I is adapted tofit accurately into one set of notches I3.I and slots I32 and projection I34 of the weight W is adapted to fit accurately into the other set of notches I3I and slots I32, when the'said'notches and slots register and at times during the performance of the mechanism, when the projection I33 is forced to fit into one set of said notches and slots due to the action of centrifugal force on the weight W or when the projection I34 of'the weight W is forced to fit into the other-set: of notches and slots by springs K the mechanism becomes inoperative, which will be more fully explained in the description of the performance of the mechanism.

The following is a description. of the performance'of an entirely torq-ue controlled speed shifting-mechanism (see Figs. loandli). Driving mesh with gear 99.

' eccentric B loosely splined on driven shaft D Collar H5 splined todriven shaft D -has arms I I6 integral with it and springs R are under predetermined compression between arms II6 and arms I-I3 integral with member E Assuming that gear C and gear (3+ are in relative positions to each other as disclosed-in Fig. 12 and that these same relative positions are had in Fig. 10. If the gear G be relatively atrest in respect to gear C and if the driving and driven shafts A and D respectivelyrotate in thesame direction, then if shaft D rotates in a clockwise direction as viewed in Fig'lO, shaft'A will rotate in :a counterclockwise directionas viewedin Figs. 12, 15 and 16 and if shaft D starts to rotate faster than shaft A member E will be rotated through arms I I6, springs R and arms I I3 causing the parts of the mechanism to take up the relative positions as shown inFig. 15, at which time a top of a tooth of gear G will contact the bottom of a tooth space of gear C A driving connection is established between the driving shaft A and driven shaft D as disclosed in Fig. 15. During the movement of shaft D just described, it had broken contact with the splines of the eccentric B (see Fig. 10) and its splines have not contacted the splines of the eccentric B ahead of it in its direction of travel, the spacing of the splines being made so that a driving connection is established before thesplines of the shaft D and the splines of eccentric B make another contact in the direction shaft D was moving. If at this point gear C rotates faster than driven shaft D is rotating the lockup of the gears as shown in Fig. 15 would be maintained and driving shaft A would drive driven shaft D through the gears C and'G? locked up and member E and eccentric B The'splines of driven shaftD and splines of eccentric B would again contact each other as disclosed in Fig. 10 as long as driving shaft A continued to drive driven shaft D However if the driven shaft D continued to rotate faster than the driving shaft A after the driving connection was established as shown in Fig. 15, then the splines of the shaft D would contactthe splines of eccentric B in the direction shaft D was moving, causing the eccentric B to be driven in a clockwise direction-as viewing Fig. 10 and a counterclockwise direction as viewing. Figs. 12, 15, and 16 and a lockup of the gears would be had as disclosed in Fig. 16, and a driving connection would be established between the driving shaft A and driven shaft D inwhich the driven shaft D would attempt to'drive driving shaft A in the same direction as the drive. .In anautomotive vehicle transmission, this would be a hold back speed.

It is obvious from the foregoing that to' establish a driving connection to cause driving shaft A tov drive driven shaft 33 or to establish a driving connection to cause shaft D to drive shaft A that the shafts A and D must bein some proximity of synchronism and that this proximity is determined by the strength of the springs R If the reverse torque driving driven shaft D was of such a magnitude as to drive shaft D exceedingly fast, and the springs R comparably stiff there would be no driving connections established as the actual time of synchronism would be so small that member E carrying gear G would be rotating so much faster than gear C that gear G would idle over gear C as the springs B would be compressed and member E would not be rotated.

When coming from a lower speed to a higher one, that is when driven shaft D would be increasing speed to equal the speed of shaft A when shaft A is rotating faster; if driven shaft D is not rotating too fast under which condition no driving connection would be established as was just pointed out, the driving connection that must be established first is the one in which the driving shaft A can drive the driven shaft D When there is no driving connection between shafts A and D if shaft A is rotating faster than shaft D gear G idles in one direction of rotation and if shaft D is rotating faster than shaft A gear G idles in the opposite direction of rotation.

If driven shaft D is rotating faster than shaft A in the direction of the dri e and slows down to a speed slightly slower than shaft A is rotating, the relative positions of the splines of shaft I) and the splines of the eccentric B will be as shown in Fig. 16 and the relative rotation of eccentric B to the member will be in a counterclockwise direction and cause a lockup of the gears G and C as shown in Fig. 15 and shaft A can drive shaft D at the speed shaft A is rotating. This performance will be more full) explained in the description of the performance of a step speed power transmission which follows in this specification.

The speed shifting mechanism disclosed in Figs. 13 and 14 is exactly like the speed shifting mechanism disclosed in Figs. 10 and 11 with the exception of the centrifugal control mechanism which is added to the mechanism disclosed in Figs. 10 and 11. This centrifugal control mechanism consists of the weight W attached to rods 1 it), which slidably fit into holes 2123 in arms I it. Also attached to rods are is a yoke I which has lugs ltd.

Springs K encircle the rods i it; and have their seats on the inner surfaces of lugs are and arms lit. The springs K normally are compressed a predetermined amount. Yoke I and weight W have projections i331; and i3 respectively, which are diametrically opposite to each other and are exactly alike in form. These projections I33 and we are adapted to fit into notches 33: of the hub E38 of the member E and slots fill of the eccentric B when the notches it! and slots 1'32 register all of which has been explained in detail in the foregoing.

When the driven shaft D is at rest and until it has attained a predetermined speed the projem tion we fits into a notch l3i and a slot M32 and locks the hub lid of member E and the eccentrio B together, and thereby permitting no relative movement of the member E and eccentric B Since there can be no relative movement of the eccentric B and member E the shifting mechanism is inoperative and the springs K hold the projection its in a notch lti and slot 832.

After the shaft D has reached a predetermined speed, the centrifugal force acting on the weight W overcomes the force exerted by the springs K to hold the projection 13s in a notch l3! and a slot E32, the projection i311 bein integral with weight W and the eccentric B and member E are no longer locked together and the mechanism becomes potentially operative whereupon a driving connection may be established. The mechanism remains operative as long a this speed is maintained and also at a higher speed until a predetermined maximum higher speed of the driven shaft 13 is attained at which time the centrifugal force acting on the weight W causes the weight to overcome the resistance of the springs K and move farther outward until the projection it? of the yoke I fits into the other set of notches ISi and slots i552 of the hub 13E! of the member E and the eccentric B respectively. The eccentric B and member E are locked together, and there can be no relative movement between the said eccentric and said member and the mechanism becomes inoperative. When the mechanism is inoperative the relation of the gears G and C are as disclosed in Fig. 12, gear G can idle and the gears operate on their pitch circles.

It was pointed out in my Patent No. 2,444,530, that in the performance of any self propelled vehicle there existed at all times a series of reverse or negative torques and positive torques and that the frequency of the changing from a positive to negative and negative to positive torque became greater as the speed of the vehicle increased. The relative movement of the member If and eccentric B is small to cause a driving connection to be established or to be disrupted. When an automotive vehicle is running the occurrences of these positive and negative torques causes the pressure to be alternated from one side of the projections [33 and H3 3 to their other side when they are fitted into a set of notches l3! and slots I32 and this reversing of pressure facilitates their moving out of the notches i3! and slots i352 when a predetermined speed of the driven shaft D is attained to cause the mechanism to be operative. Also these positive and negative torques facilitate the moving of projection l33 of the yoke l into a set of the notches Hi and slots 132, when the maximum predetermined speed of driven shaft D is attained to cause the mechanism to be inoperative.

Referring to the drawings, Figs. 17, 18, 19, 20 and 21 disclose a speed-shiftin mechanism for the high speed of a step-speed power transmission for an automotive vehicle. The salient difference of this shifting mechanism comparable to the ones just described is that there must be embodied in it a definite hold back mechanism 01' in other words there must be a mechanism to prevent at all times the driven shaft from running faster than the driving shaft which would be at the speed of the motor.

A gear his (see Fig. 18) is integral with a shaft directly connected with the motor which will be more fully explained and understood from the description of a complete step-speed transmission that follows. Ball bearing MI is conventionally held in receptacle I42 in gear M9. The extreme end of driven shaft D is conventionally journaled in ball bearing I4l. Hollow driving shaft A has projections 143 which fit into slots Hi l in the inner end of gear Hill and the driving force is transmitted from gear Mil to driving shaft A in this manner. Driving shaft A is mounted on driven shaft D and is free to rotate about said shaft on needle bearings NH entailing the usual conventional construction.

Gear C is integral with the driving shaft A and meshes with gear G mounted on fixed shaft accesses- 105' integm with' membenE and free to rotate about' fixed'shaft IIl-=on needle' bearings I06" entailing the usual conventionalconstruction. A

collarIO'I fits on-the outer end of fixed shaft I05 andis held in place-by a-taperedpin- I08; whichpierces both the fixed-shaft I05'--and collar IIl-Ii One end of gear-"G movably abuts the insidesurfaceof -collar- I01 and-the other end of gear-- G movably abuts the face of hose I09 of the Member E is-mounted on and free member E to rotate-about eccentric-B Eccentric B is loosely splined ondriven-shaft the manner I as shown in Fig.2l. 1

Gear C integral-with-driving shaft A also meshes with gear G mounted onfixed shaft -'I I" integral with the member E and is free to rotate about shaft I95 on needlebearings I06 entailing'th'e usualconventionalconstruction. 1 A 001- movably abuts the face of boss I09 of the mom-2.:= Member E is mounted on an eccentric B splined on shaft D in splines I I0"as shown in ber E Fig. 20and is free to rotate about the eccentric The splined portion of drivenshaft D loosely pierces holes II4' and H4" in members E and E and-oneend of eccentric B and eccentric B a movably abuts the faces of bosses shown in broken lines, integral with members E and E anden'circling holes H4 and H4 respectively; Counter balancing weight H2 is integral with member E The-face of boss III of member E movably abuts the inner end of driving shaft A and the face of boss 'III of member E movablyabuts one end of eccentric B One end of eccentric B abuts the inner end of collar H5 splined to driven shaft D in splines H0. Arms H6" are integral with collar I I5" and extend toward the clriv'ing'end of the mechanism and arms I I3" are integral with member E Springs R under suitablecompression have their seats in circular recesses (not shown) in arms H3 and H6 of the member E and collar Ears I 45-are integral with member lll and are adapted to contact arms H6 and limit the movement of the member E in one direction about-the eccentric B Rods I I9, slidably fit into holes I46 in weights W fit tightly in holes" I23 in arms I I6 integral with the collar H5 and are held fast in holes I23 byitapered pins I I! which pierce the arms H6" and the rods H9. Springs K fit loosely into holes I48 in the weights W and are conventionally fastened to the collar II5 at one of bores- I5lof the holes I45 in weights W and the inner surfaces of these heads are adapted to con tact the bottoms of counter bores I5I and limit theoutward movements of the Weights -W A projection I34 on the side of one of the weights W is adapted to fit into a notch I3 I Whose sides slope inwardly toward each other, locatedin the hub 130 in member-E and also into-a'slot I32" rectangular in section and cut into the eccentric- I I5 respectively.

B "(see Figs2 -18 and 21) wandfiloclf the hub [3051 v and eccentric B sot there: can be 1 :'-no :relative movement between theml:

The zi erformance nf the high-speed shifting mechanism cannot be operative .until a predetermined speed of the automotive vehicle :has been attained and-continues operative as longas-the vehicle maintainsa speed above the :predeter mined spe'ed Also the -driven=shaft D can never .1

rotate fas'ter-: than the driving shaft A Other wise-#the performance isthesame-as the shifting mechanism immediatelyheretoforedescribed:

When the driven shaft D has -:attained sub?v stantially l the predeterminedspeed, iweights W due to centrifugal force-acting on them move outwardly againstthe spring tension of springs K projection 134" moves out 0f notch I3I' of hubIBNand slot I32 ofthe eccentricB2, menu-- ber- -E and eccentric B :may have relative' movement and the mechanism is potentially operative 1 whereupon adrivin'g connection: may be establishe'd; lfthe speed of the driven shaft-D decreases substantially I below the predetermined r speed-, the' centrifugal-force acting on weights W cannot overcome-the spring tension ofsprings K the springsdraw the weights W inwardly, projection I34 -integral:-withone-of theweights W enters notch- 131 and slot I32; and there can be no relative movementofmember E and ec- -centric' B themechanism-isinoperative and a drivi-ng connecti'on cannot be established.

Assuming-that the driving. shaft A and driven shaft D rotate in the same direction and that: shaft D -is rotating-in aclockwise direction, as

viewed in -Fig5-17,- then alsoas viewed in Figs. 20

and -21the shaft D wou1dbe rotating in a clockwise direction. But as viewed in-Figzl9 the drivshould atter'npt to-rotate fastenthan gearC or faster than-themotorwas-running, that the ec-- centric B splinedto driven shaft D would cause gear-G through the -member E to be pulled: inwardly 'and there would-be a lockup of gears G and geaI C and shaft D couldnot rotate'faster than-gear 0 which rotates-at the speedofthe moton Againviewing Fig. 20 it will be seen that .7 if member E shouldattempt to rotate about eccentric B in' a counterclockwise direction to I cause=a lockup of -gears G and C it would not be permitted to rotate-in this direction as the ears I45-would contact arms l I6 and the relative positions of the parts would be as disclosedin' 'v Fig.-20;-

The following is the description of a low speed shifting mechanism which also functions-as an automatic clutch replacing the main clutch which is usually located :between the motor and the transmissionx Since one view of this low speedvmechanism and automatic clutch is shown installed in a step-speed transmission the driven shaft isnowthefioating shaft of the transmis- 'sionand is designated by the reference character F (see :F'igs..22, 23,245 and 25). Gear I55 is keyed needle bearings-I58 and I59'(see Figs. 22 and 25). lOne side fgear I55; opposite the side of its 15 counter bore abuts a ring I60, which in turn abuts the inner ring of ball bearing Ifil. Ball bearing [6| is conventionally held in receptacle I62 in the front end of the auxiliary housing 1? of the transmission. Hollow driving shaft A is journaled in ball bearing IIiI.

Eccentric B is integral with driving shaft A Member E is mounted on the said eccentric B and is free to rotate thereon. One end of member E movably abuts the side of an enlarged portion I63 of driving shaft A The other end of member E movably abuts the side of a split plate I64, having the same eccentricity as the eccentric B Split plate Ifid fits on a smooth portion of floating shaft F, and has a circular disc portion I65 that fits into a counter bore in the eccentric B and the other side of the said plate abuts splines I86 on floating shaft F (see Fig. 22). Counter balancing weight II2" is integral with member E A gear C is tightly splined on floating shaft F on splines I66, one end of gear C abuts a side of the split plate I64 and the other end of the said gear abuts an end of clutch member I67. Gear meshes with gear G mounted on needle bearings I68 on fixed shaft I69 integral with member E A collar I70 fits on the end of fixed shaft I59 and is held in place by a tapered pin I7I which pierces both the collar I70 and the shaft I69. One side of gear G movably abuts a face of the movable member E and the other end of gear G movably abuts the inner side of collar I70.

Rods H9 fit tightly in holes in arms I72, which are integral with hollow driving shaft A and are held in place by tapered pins I73 which pierce both the rods H9" and the arms I72. Weights W and W fit slidably over rods I I9" in suitable holes in the weights (see Fig. 24). Yoke I is integral with weight W and yoke I is integral with weight W Springs K located in holes I43 in the weights W and W and holes H33 in the arms I72 are under a predetermined tension and their ends terminate in hooks which fit around grooves in rods I4 9 that fit into partially semicircular grooves I5il in the weights W and W (see Figs. 22, 23 and 2e). Tapered holes I73 in the hub I36" of the member E and spherical shaped holes I74 in the eccentric B are adapted to receive pins I75 formed to fit the said holes when they register with each other. Pins I75 have cylindrical portions smaller than the greatest diameter of their tapered portion, that are pressed fit into suitable holes in the weight W and the yoke I which is integral with weight W (see Fig. 24)

In order to have the low speed shifting mechanism function both as a clutch and shifting mechanism it is obvious that the parts must be made heavier, since the speed of its driving shaft would be much slower than the motor speed and the weights W and W must be heavier. Before the starting of the motor the relation of the parts of the mechanism to each other are as disclosed in Fig. 24. Pin I75 in weight W (shown in broken lines) fits into tapered hole I73 in the hub I30" of member E and into spherical shaped hole I'M in the eccentric B thus locking the member E and eccentric 13 together, there can be no relative movement between them, the mechanism is inoperative and a driving connection cannot be established.

When the driving shaft A of the mechanism attains a predetermined speed, the centrifugal force acting on the weights W and W overcome the tension of springs K the weights move outwardly and the pin I75 attached to Weight W moves out of the tapered hole I73 and spherical shaped hole I74, and there can be relative move-- ment of the eccentric B and member E and the mechanism is potentially operative whereupon a driving connection may be established. While the motor was increasing in speed to cause the driving shaft A to attain the predetermined speed, gears C and C were meshing with gears G and G respectively and were imparting some driving force to floating shaft F through members E and E through eccentrics B and B respecttively (see Figs. 14 and 18). Also gear G meshing with gear C was imparting some driving force to gear C As the speed of the motor increased the driving force imparted to floating shaft F due to the meshing of the gears just described also increased and a drive was imparted to floating shaft F analogous to the driving force imparted by a slipping clutch, which was pointed out in the description of the performance of the clutches described in the early part of this specification thus facilitating gradual easy star-ting of the vehicle.

After shaft A has attained the predetermined speed, at which time the mechanism is potentially operative whereupon a driving connection may be established, eccentric B integral with driving shaft A moves relative to member E and causes gear G to be drawn inwardly and a lockup is established between gears G and C splined to floating shaft F on splines I65 and the floating shaft F is positively driven through the low shifting speed mechanism.

Floating shaft F will continue to be driven through the low speed shifting mechanism as long as the speed of driving shaft A maintains the predetermined speed and until a higher predetermined speed of shaft A is attained. At the higher predetermined speed, the centrifugal force acting on the weights W and W has caused them to overcome the tension of springs K and arrive at the outwardmost point of their travel. Yoke I integral with "weight W has been drawn inward until pin I75 attached to yoke I has entered into a tapered hole I73 in the hub I38" of member E and spherical shaped hole lit in the eccentric B, member E and eccentric B are locked together, they can have no relative movement, the mechanism is inoperative and a driving connection can not be established. The mechanism will remain inoperative as long as the speed of driving shaft A is higher than, or at, the higher predetermined speed.

When the speed of driving shaft A decreases below the higher predetermined speed, the weights W and W move inwardly, since the springs K exert a greater pull on the weights than the centrifugal force acting on the weights can exert. Yokes I and 1'. move outwardly when weights W and W move inwardly, as yokes I and I are integral with weights W and W respectively. As yoke I moves out, pin I 7 5 attached to it moves out of tapered hole I73 in the hub I30 of member E and spherical shaped hole I74 in eccentric B and there can be relative movement of member E and eccentric B and the mechanism is operative, and driving shaft A through the low speed shifting mechanism can drive floating shaft F. Driving shaft A will continue to drive floating shaft F until the speed of shaft A has decreased to the low predetermined speed at which time the springs K have pulled the weights W and W to the inwardmost point of their travel and pin I15 attached to weight W has entered the tapered hole I13 in the hub I30" and spherical shaped hole I'M in the eccentric 13. Under the conditions just described the mechanism becomes inoperative and a driving connection cannot be established. It is obvious if the speed of shaft A be decreased not to the predetermined low speed when the mechanism is operative, but increased after a certain amount of decrease in speed, if it continues to increase in attained the mechanism would become inoperative by the same functioning of the parts as heretofore described in detail. The pins I75 moving into and out of tapered holes I13 and spherical shaped holes I'M is greatly facilitated by the characteristic of the changing from positive to negative torque and negative to a positive torque in the. performance of an automotive vehicle which has been explained heretofore.

A'ball bearing I16 conventionally held in receptacle I'I'! in clutch member I61 journals the inner end of tail shaft T of the transmission. The end of a smooth portion I78 of tail shaft T, larger than the portion of the said tail shaft which fits into the ball bearing I16 abuts one end of the inner ring of ball bearing i'Ifi. One side of spring ring I19, which fits into an annular groove I80 in tail shaft T, abuts the ends of splines I8! of tail shaft T and its other side abuts one end of the of lubricant fits onto the smallest cylindrical portion I86 of the adapter I84 and is conventionally held in an annular recess in the auxiliary housing P.

Gear I81, which is the first of the reverse gear W train, is integral with clutch member I61 and A shaft journaled in a meshes with gear I88. suitable journal integral with housing P (shaft and journal not shown), has rotatively attached topics of its ends gear I88 and has rotatively attached at its other end gear IS9. The drive imparted by gear I81 to I88 is transmitted by gear I88 through the said shaft to gear I635. Gear I85 mesheswith an idler gear I9!) which rotates about a shaft suitably held in the auxiliary housing P (the shaft not shown) Th inner surface of head it! of the said shaft is mova-bly a'butted by one end of idler gear 1-90 and the other end of gear I90 movably abuts the face of boss I92 integral with the auxiliary housing P.

A clutch member I93 is slidably splined on tail shaft T on splines i8 I. A gear ltd is integral with clutch member i 93 and is adapted to mesh with idler gear I98. Teeth I95 of clutch'member I93 are adapted to engage teeth I96 of clutch member IBI splined to floating shaft F in splines Hit.

An annular groove It! in clutch member I93 receives shifting fingers I88.

Aperture E99 in auxiliary housing P has a cover plate 294'} fastened to auxiliary housing P by bolts 2M threaded in said housing. Conventional loci: washers are located under the heads. of bolts 2i]! to prevent them from turning when tightened. An annular projection 262 of auxiliary housing P fits into an annular recess 2&3 in the main housing Q. One set of bolts 2% fit into holes 265 in main housing Q and are threaded in holes 265 in the auxiliary housing P. Another set of bolts speed until the higher predetermined speed is 1% 2t? fit into holes 268 in auxiliary housing P and and threaded in holes 253% in the main housing Q. Conventional lock washers are located under the heads of all the bolts to prevent them from turning when tightened. When bolts 2% and it? are tightened in their threads annular projection 292 of the auxiliary housing P tight into annular recess 233 of the main housing Q and the faces of said housing abut each other under pressure. Aperture Ziil in the main housing Q has a cover plate 25 I fastened to main housing Q by bolts 2 l 2 threaded in the main housing.

A longitudinal section through'a portion of a step-speed transmission is shown in Fig. 25 and embodies a high speed shifting mechanism X which has been described, and disclosed in Figs. l7, l8, 19, 29 and 21 of the drawings and also embodies an intermediate speed shifting mechanism Y which has been described, and disclosed in Figs. 1e), l1, l2, l3, 14, 15 and 15.

Driving shaft S connecting the motor with high speed shifting mechanism X is journaled in ball bearing 2 is conventionally held in receptacle 21d in the front end of the main housing Q. A counter shaft V at one of its ends is journaled in a ball bearing Zia conventionally held in receptacle 256 in the end of the main housing Q and is journaled at its other end in ball bearing Zii conventionally held in receptacle N8 in the front end of auxiliary housing P. Gears 2E9, 228 and 22S are integral with the counter shaft V. Gear lit integral with the driving shaft S meshes with gear 2 is of the counter shaft V and the drive from the motor is transmitted through gears Hit and EL? to the counter shaft V. The drive is transmitted from the counter shaft V to the shifting mechanism Y by gear 222 meshing with gear 99 which is keyed to driving shaft A of the intermediate speed shifting mechanism Y. Gear 272! of the counter shaft V meshes with gear E55 which is keyed to the driving shaft A of thecombination low speed shifting mechanism and automatic clutch Z.

The following is a description of the performance of the step-speed transmission as disclosed in Figs. 22 and 25, all the shifting mechanisms X, Y and Z being both torque and centrifugally controlled. Assume the motor is running at a slow speed causing shaft A of shifting mechanism Z to be rotating at a speed below the predetermined speed at which shifting mechanism Z becomes operative. Relative positions of the clutch members it? and I83 in Fig. 22 discloses that the transmission is in neutral. In order to have the motor drive the tail shaft T and propel the automotive vehicle forward if the transmission be installed in an automotive vehicle, the motor is assumed to be running in a counter clockwise direction as viewed toward the broken end of driving shaft 6, the shifting fingers 93, by any conventional means, must be moved forward carrying clutch member 93 with them until the teeth 895 of clutch member I93 engages correctly teeth it? of clutch member iill. The speed of the motor now being reasonably gradually increased, the meshing of gears C and C with gears G and G respectively, as gears C and C would be rotating faster than shifting mocha nisms Y and X, would be rotating bodily and the meshing of gear G with gear C as the mecha:

Ziii counter shaft V gears 225 and i55 would be- When such as to cause driving shaft A to attain the predetermined speed required to cause shifting mechanism Z to be operative, there would be a lockup of gears G and C and the floating shaft F and tail shaft T, now connected to gear ilil would be driven through low speed shifting mechanism Z.

If the motor speed continued to increase, the driving shaft A of shifting mechanism Z through. the gearing just described will be increased to the higher predetermined speed at which time the shifting mechanism Z will become inoperative. It being so timed, by proportioning the weight W and spring K of the shifting mechanism Y, that just before shifting mechanism Z became inoperative, due to driving shaft A attaining the higher predetermined speed, shifting mechanism Y became potentially operative and a driving connection could be established. With the average driving there will be a reverse torque and the speed of shifting mechanism Y rotating bodily will be sufficiently near synchrcnism with the speed of gear (2 integral with driving shaft A that springs R will permit a lockup of gears G and C the details of how th se lockups occur have been described several times heretofore in this specification, and after this lockup of gears G and C, floating shaft will be driven through shifting mechanism Y and in turn drive tail shaft T.

If the motor speed now be continued to increase, the weight W of speed shifting mechanism Y, due to centrifugal force, will be moved farther outwardly until the projection :33 of the yoke I being pulled inwardly fits into notch i3! of the hub I36 of the member E and slot I32 of the eccentric B and the shifting mechanism Y becomes inoperative (see Figs. 13, 14 and 25). With the average driving a reverse torque will again occur and floating shaft F will attempt to rotate faster than driving shaft A of shifting mechanism X is rotating, driving shaft A being rotatively attached to gear Mb as afore described and gear Hi0 being integral with shaft S directly connected with the motor. Just before the shifting mechanism Y became inoperative, it being so timed by proportioning of the springs K and weights W the weights W due to centrifugal force had moved outwardly until the projection Hi4 integral with one of the weights W had moved with its weight W out of notch E3! of hub l3i) of member E and out of slot I32 of the eccentric B and mechanism X became potentially operative and a driving connection could be established (see Figs. 17, 18, 21 and 25) Floating shaft F cannot rotate faster than driving shaft A as eccentric B tightly splined to floating shaft F in splines 4 iii will rotate in a clockwise direction as viewing Fig. and cause member E to move inwardly, pull gear G inwardly and there will be a lockup between gear G and gear G which is integral with driving shaft A At the same time collar iiti" tightly splined to floating shaft F in splines lib, through its arms H6" and springs R drove member E in a clockwise direction, as viewing Fig. 20, gear G was pulled inwardly and a lockup was established of gears G and C and the mechanism X has driving connections between driving shaft A and floating shaft F for shaft A to drive floating shaft F and for floating shaft F to drive driving shaft A in the direction the motor is rotating. As long as the speed of the motor is maintained sufficiently high, that the floating shaft F maintains a speed so that weights W remain out at a point that projection I34 does not enter note 20 I3I' and slot I32 (see Figs. 18, 21 and 25), floating shaft F will be driven at the speed of the motor.

If the speed of the motor be reduced, either by demand of the vehicle performance or manually slowing down by closing the throttle, to a point where the centrifugal force acting on weights W cannot overcome the tension of the springs K so that the projection 3 3 enters the notch I3! and slot l32 the shifting mechanism X becomes inoperative and the driving shaft A can no longer drive floating shaft F but floating shaft F can always drive driving shaft A in the direction of the drive if the floating shaft F rotates faster than driving shaft A as there will be a lockup of the gears G and C which has been described heretofore (see Figs. 19 and 20).

Just before the motor had slowed down sufficiently to cause the shifting mechanism X to become inoperative as just described, the floating shaft F had slowed down so that weight W of the shifting mechanism Y had moved inwardly and the projection I33 of yoke I had moved out of notch l3! and slot I32 of the hub 53% of the member E and eccentric B of the shifting mechanism Y and shifting mechanism Y became potentially operative and a driving connection could be established (see Figs. 13, 14 and 25). When the shifting mechanism X became inoperative the motor increased its speed slightly and the speed of the driving shaft A of the shifting mechanism Y and the speed of floating shaft F became sufficiently near synchronism that there was a lockup of the gears G and C the eccentric B being driven in a counter-clockwise direction by the relative movement of floating shaft F in a counter-clockwise direction relative to member E as viewing Fig. 10 and the floating shaft F is driven through gears I48 and 2 i 9, counter shaft V, gears 22D and 99, driving shaft A and through the shifting mechanism Y (see Figs. 13, 14 and 25).

The floating shaft F will be driven through the gearing just described and shifting mechanism Y until the speed of the floating shaft F decreases to a speed where the weight W acted on by centrifugal force cannot overcome the spring tension of springs K the weight W moves inwardly and projection i341 integral with weight W moves into the notch I32 and slot I3! of the movable member E and eccentric B the shifting mechanism Y becomes inoperative and floating shaft F will be driven through the shifting mechanism Z, which will be more fully explained in the following.

But if while the drive is through shifting mechanism Y, the motor speed is increased, thereby increasing the speed of floating shaft F to a speed where the centrifugal force acting on the weight W causes the weight W to move outwardly against the tension springs K until the projection I33 of yoke I moves into notch i3! of the hub I30 of the member E and slot ii of eccentric B the shifting mechanism Y becomes inoperative and the floating shaft F will be driven through shifting mechanism X. The details of this performance has been described heretofore.

Just before the speed of floating shaft F had decreased to a point where the shifting mechanism Y became inoperative as just immediately heretofore described, weights W and W, of shifting mechanism Z, on account of the centrifugal force acting on them being no longer sufiicient to 21 overcome the tension ofsprings K had" moved inwardly until the pin H5 attached to the yoke I integral with weight W which moves outward when weight W moves inwardly, had moved out of tapered hole I13, in the hub 13B of member E and spherical hole I14 of the eccentric B and the shifting mechanism Z had become potentially operative and a driving connection could be established (see Figs. 22, 23 and 24) In the same manner as the speed of the floating shaft F and driving shaft A of the shifting mechanism Y became sufficiently near synchronism to cause a lockup of gear G and when the shifting mechanism X became inoperative, as just described, so now driving shaft A of the shifting mechanism Z and the floating shaft F are sufiiciently near synchronism that there is a lockup of gear G and gear C of the shifting mechanism Z and the floating shaft F is driven through shifting mechanism Z. If the motor speed is not increased, the drive will continue through gear I40 and gear 219, counter shaft V, gears 221 and W5, driving shaft A and through the shifting mechanism Zto drive floating shaft F. If the speed of the motor be decreased to a predetermined idling speed weights W and W will be drawn farther inwardly to their furthermost point inwardly, as the weights W and W are so proportioned in respect to springs K pin I75 attached to the weight W will enter tapered hole I13 and spherical hole I74, the shifting mechanism Z will become inoperative, the details of this performance have been described heretofore, and there will be no positive drive between the motor through any of the shifting mechanisms X, Y and Z and the floating shaft F. If the motor is run near or at the top idling speed there will be the equivalent of a slippingclutchas a driving force will be imparted to the floating shaft F by the meshing of gears C and G C and G and C and G which has been described heretofore.

In the foregoing description of the performance of the step-speed transmission, the expression average driving was employed in this description. When the shifting of the speeds are from a lower to a higher speed, there must be a reverse torque or in other words floating shaft F must rotate as fast or attempt to rotate faster than the driving shaft of the next speed higher than the one it just previously had been driven through in order that the floating shaft F and the said driving shaft be sufficiently near synchronism that a driving connection may be established as has been explained. It is natural with operators to permit their foot to dwell on the throttle or actually ease up on the throttle in the operating of manually speed shifting transmissions of all types, and this easing up or dwelling of the throtg,

tle is necessary in the driving of this transmission in shifting from a lower to a higher speed, that is what is intended to be the meaning of the ex-v pression average driving. However, the shifting mechanisms that are both torque and centrifugally controlled, in shifting from a higher to a lower speed will operate with or without the dwell of the throttle.

It will be obvious from the foregoing that both torque and centrifugally controlled and only torque controlled shifting mechanisms are an elaboration of the two-way overriding mechanism disclosed in Figs. 1, 2, 3 and l. Springs R and R function similarly as springs R in the device disclosed in Figs. 8 and 9 and heretofore described; in that when floating shaft F is sufficiently out of synchronism with driving shafts A and A that whether the gears C and C are ro-' tating faster than gears G and G respectively or gears G 'and'G are being carried around gears C and C respectively faster than gear C and C are rotating, therecan be no driving connection established, until there is a near proximity of synchronism of the floating shaft F and one or the other of shafts A and A The tension which springs R and R are under determining that proximity and they also provide the slipping device performance to secure easy and gradual starting of the vehicle and in this last function they perform exactly like springs R in the construction disclosed in Figs. 8 and 9. Also these springs R and R function to make the transmission selective by the manipulation of the throttle. In any type of vehicle in which this transmission is installed, if it be operating'in any of the speeds other than high speed, if the operator opens the'throttle to secure a high road speed for any speed in which the vehicle is operating, then close the throttle quickly a reverse torque will be had due to the road speed of the vehicle, such that the floating shaft F will be rotating so much faster comparable to even one or more driving shafts A if the transmission had several intermediate speed shifting mechanisms, that the springs R would be compressed and the floating shaft F would not drive member E? through the springs R in the direction the floating shaft F was rotating to cause a driving connection to be established through that speed mechanism, but the driving connection would be established in a higher speed mechanism in which a driving shaft A or even A would be rotating nearer the speed of the floating shaft F. For example: in the three speed transmission disclosed in the draw ings, if installed in an automotive vehicle, and operating through the low speed shifting mecha-' nism Z if the throttle was opened wide and a higher road speed than usual be given the vehicle, then the throttle be closed quickly, the transmission could be caused to perform in the high speed shifting mechanism X, since the floating shaft F would have to synchronize in this speed because there would be a locking up of gears G and C to prevent the floating shaft F from rotating faster than driving shaft A it being understood that the throttle must be opened again in a reasonable tirneto causethe speed of the motor to be adequate for the shifting mechanism X to be operative.

Likewise this transmission performing such that the drive was through any shifting mechanism other than the low speed shifting mechanism, can be caused to operate through a lower speed mechanism by a reasonably slow closing of the throttle and then opening it quickly. This causes a very low frequency of first a reverse or negative torque then a positive torque. Again springs R or R would be compressed, the floating shaft F would not drive member E or member E in the direction it was rotating to cause a driving connection to be made in the speed shifting mechanism through which the floating shaft was being driven before the just described manipulation of the throttle and the drive would be established in a lower speed shifting mechanism.

If any type of vehicle equipped with an internal combustion engine be also equipped with this transmission and is being driven through any speed other than the low speed shifting mechanism, the transmission will not permit the engine to stall, because at the stalling point of the engine there always occurs a series of negative and positive torques of low frequency, similar to the low frequency negative and positive torques manually secured as just described. When negative and positive torques occur of low frequency the drive will be had through a lower speed shifting mechanism. The value of these positive and negative torques of low frequency can be experienced in the plate clutch type passenger automotive vehicle, when attempting to start the vehicle in high speed from a standstill. Under such conditions the vehicle will have a series of jerky motions and in most cases the engine will stall.

To reverse the directions of the rotation of tail shaft T to drive a vehicle backward in which the transmission is installed, a conventional construction is employed (see Fig. 22). Fingers I98 are moved by any conventional manually operated means to cause clutch member I93 slidably splined to tail shaft T in splines I81 to be moved to the right as viewing Fig. 22 and gear I94 integral with clutch member I93 is caused to mesh with idler gear I99. This reverse train of gears has been described in the foregoing.

Since this transmission is more particularly intended for self-propelled rail-cars, army-tanks, heavy trucks and busses, in which expert operators are employed the following described design is the intention of the applicant. An automatic device of the form disclosed in Figs. 5, 6 and '7 and described in this specification would be located between the motor and the transmission itself. This device is a form of construction of applicants pending application, Serial No. 671,089, filed May 20, 1946. The shifting mechanisms of the transmission would be torque controlled only. All intermediate shifting mechanism would be as disclosed in Figs. 10, 11 and 12. The high speed shifting mechanism would be the same as that disclosed in Figs. 10, 1'1 and 12 and have added to it a definite hold back speed mechanism as is disclosed in Figs. 18, 19 and 20, consisting of eccentric B tightly splined to floating shaft F, member E mounted on eccentric B and having ears I45 integral with it and adapted to contact arms I IE" to prevent its rotation in one direction about the eccentric B and having a gear G adapted to lockup with gear thereby insuring that the floating shaftF under all conditions of the performance of the transmission can never rotate faster than the motor is rotating. A two-way overriding mechanism such as is disclosed in Figs. 1, 2, 3 and a would comprise the low speed shifting mechanism. Since the low speed shifting mechanism is the only shifting mechanism in which its eccentric is attached to its driving shaft, which is driven through gearing and the counter shaft by a gear rotatively attached to the main driving shaft of the transmission, when the main driving shaft of the transmission would start to rotate, eccentric B would rotate (see Fig. 22) and a lockup of gears G and C would be established to cause the drive to be through the low speed mechanism to drive the floating shaft F. Floating shaft F, at the start of the rotation of the main driving shaft of the transmission would always be driven first through the low speed shifting mechanism if only for an instant.

The manually operated mechanism for the pur-- pose of securing forward, neutral and reverse driving connections would be located between the floating shaft F and the tail shaft T of the transmission. Clutches would be employed in this mechanism that could be engaged or disengaged practically as easily under load as under no load. A clutch which has these characteristics and 2d manually operated is disclosed in the applicants pending application for patent Serial No. 671,089, filed May 20, 1946.

In this purely torque controlled transmission, as it has been pointed out in the foregoing, the operator can shift from one speed to another by manipulation of the throttle. If it is desired to shift from a lower speed to a higher one, the throttle is closed quickly and opened reasonably gradually. If it is desired to shift from a higher speed to a lower one, the throttle is reasonably slowly closed and quickly opened. Also it has been pointed out that if the transmission be operating through any of the shifting speed mechanisms, that if the load becomes too great to cause the motor to slow down to the stalling point, the transmission automatically shifts to a lower speed and will not permit the motor to stall, because of the occurrence of a series of negative and positive torques of low frequency, a natural characteristic of the performance of an internal combustion engine at the stalling point in an automotive vehicle.

In the foregoing it has been described how the operator by manipulation of the throttle can shift from a lower speed to a higher and from a higher to a lower one. If the operator would require the motor to operate as a brake, this can be done in any speed shifting mechanism through which the drive is operating by reasonably gradually closing the throttle and the hold back lockup of the gears will be established and remain established until the throttle is opened again sufiiciently to cause the motor to take over the driving. With this design of transmission just described, a selective step-speed transmission is had with as many different gear ratios as may be required, having as many speeds backward as forward and all speed shifting is accomplished readily and easily by the manipulation of the throttle controlling the speed of the engine.

I claim:

1. A mechanism having a driving and a driven element rotatable about a common axis of rotation, a gear rotatively attached to one of the elements, a member carried by the other element adapted to rotate about an axis of rotation spaced from the common axis of rotation of the elements, a gear carried by the member functioning as a means to establish and disrupt the driving connection between the elements, adapted to mesh with the first said gear, to rotate about its own axis of rotation and rotate bodily about the axis of rotation of said member, means to permit a predetermined limited amount of rotation of the axis of rotation of said member about the common axis of rotation of the elements, a positive driving connection between the said other element and said member to rotate the member about its own axis of rotation, means to permit the positive driving connection to be inoperative at times for a predetermined part of a revolution of the said other element and resilient driving connections between the said other element and said member to rotate the member about its own axis of rotation, when the positive driving connection is inoperative and to maintain predetermined relative positions of the said other element and said member when the driving connection between the elements is disrupted.

2. A mechanism having a driving and a driven element rotatable about a common axis of rotation, a gear rotatively attached to one of the elements, a member carried by the other element adapted to rotate about an axis of rotation spaced '25 from the common axis of rotation of the elements, a gear carried by said member functioning as a means to establish and disrupt the driving .connection between the elements, adapted to mesh with the first said gear, to rotate about its own axis of rotation and rotate bodily about the axis of rotation of said member, means to permit a predetermined limited amount of rotation of the axis of rotation of said member about the common axis of rotation of the elements, a positive driving connection between the said other element and said member to rotate the member about its own axis of rotation, means to permit the positive driving connection to be inoperative at times for a predetermined part of a revolution of said other element, resilient driving connections between the said other element and said member to rotate the member about its own axis of rotation, when the said positive driving connection is inoperati" a and to maintain predetermined relative positions of the said other element and said member when the driving connection between the elements is disrupted, and a second member carried by said other element adapted to rotate about an axis of rotation spaced from the common of rotation of the elements, means to prevent the second member from rotating in one direction of rotation about its own of rotation, a gear carried by the second member functioning as a means to establish and disrupt a driving connection between the elements, adapted to mesh with the first said gear, to rotate about its own axis of rotation and rotate bodily about the axis of rotation of the second. member.

3. In a step-speed power transmission in combination, a speed-shifting mechanism having a driving and a driven element rotatable about a common axis of rotation, a gear rotatively attached to one of the elements, a member carried by the other element adapted to rotate about an axis of rotation spaced from the common axis of rotation of the elements, a gear carried by said member functioning as a means to establish and disrupt the driving connection between the elements, adapted to mesh with the first said gear, to rotate about its own axis of rotation and to rotate bodily about the axis of rotation of said member, means to permit a predetermined limited amount of rotation of the axis of rotation of said member about the common axis of rotation of the elements, a positive driving connec tion between the said other element and said member to rotate the member about its own axis of rotation, means to permit the positive driving connection to be inoperative at times for a predetermined part of a revolution of the said other member,- resilient driving connections between the said other element and said member to rotate the member about its own axis of rotation when the positive driving connection is inoperative and to maintain predetermined relative positions of the said other element and said member when the driving connection between elements is disrupted and means controlled by the speed of one of the elements for locking said member against rotation about its own axis of rotation until a predetermined speed of said one of the elements is attained.

4. In a step-speed power transmission in combination, a speed-shifting mechanism having a driving and driven element rotatable about a common axis of rotation, a gear rotatively attached to one of the elements, a member carried bythe other element adapted to rotate about an 26 axis of rotation spaced from the common axis of rotation of the elements, a gear carried by said member functioning as a means to establish and disrupt the driving connection between the ele-- ments, adapted to mesh with the first said gear, to rotate about its axis of rotation and rotate bodily about the axis of rotation of so i member, means to permit a predetermined limited amount of rotation of the axis of rotation of said member about the common axis of rotation of the elements, a positive driving connection between the said other element and said member to rotate the member about its own axis of rotation, means to permit the positive driving connection to be inoperative at times for a predetermined part of a revolution of the said member, resilient driving connections between the said other element and said member to rotate the member about its own axis of rotation when the positive driving connection is inoperative and to maintain predetermined relative positions of the said other element and said member when the driving connection between the elements is disrupted, a second member carried by said other element adapted to rotate about an axis of rotation spaced from the common axis of rotation of the elements,

means to prevent the second member from rotating in one direction of rotation about its own axis of rotation, a gear carried by the second member functioning as means to establish and disrupt a driving connection between the elements, adapted to mesh with the first said gear, rotate about its own axis of rotation and rotate bodily about the axis of rotation of said second member, and means controlled by the speed of one of the elements for locking said member against rotation about its own axis of rotation until a predetermined speed of said one of the elements is attained.

5. In a step-speed ower transmission in com bination, a speed-shifting mechanism having a driving and a driven element rotatable about a common axis of rotation, a gear rotatively attached to one of the elements, a member carried by the other element adapted to rotate about an axis of rotation spaced from the common axis of rotation of the elements, a gear carried by said member functioning as a means to establish and disrupt the driving connection between the elements, adapted to mesh with the first said gear, to rotate about its own axis of rotation and to rotate bodily about the axis of rotation of said member, means to permit a predetermined limited amount of rotation of the axis of rotation of said member about the common axis of rotation of the elements, a positive driving connection between the said other element and said member to rotate the member about its own axis of rotation, means to permit the positive driving connection to be inoperative at times for a predetermined part of a revolution of the said other member, resilient driving connections between the said other element and said member to rotate the member about its own axis of rotation when the positive driving connection is inoperative and to maintain predetermined relative positions of the said other element and said member when the driving connection between elements is disrupted and means controlled by the speed of one of the elements for locking said member against rotation about its own axis of rotation prior to a predetermined speed and subsequently of another predetermined speed of said one of the elements.

6. In a step-speed power transmission in combi- 2.7 nation, a speed-shifting mechanism having a driving and a driven element rotatable about a common axis of rotation, a gear rotatively attached to one of the elements, a member carried by the other element adapted to rotate about an axis of rotation spaced from the common axis of rotation of the elements, a gear carried by said member functioning as a means to establish and disrupt the driving connection between the elements, adapted to mesh with the first said gear, to rotate about its axis of rotation and rotate bodily about the axis of rotation of said member, means to permit a predetermined limited amount of rotation of the axis of rotation of said member about the common axis of rotation of the elements, a positive driving connection between the said other element and said member to rotate the member about its own axis of rotation, means to permit the positive driving connection to be inoperative at times for a predetermined part of a revolution of the said other member, resilient driving connections between the said other element and said member to rotate the member about its own axis of rotation when the positive driving connection is inoperative and to maintain predetermined relative positions of the said other element and said member when the driving connection between the elements is disrupted, a second member carried by said other element adapted to rotate about an axis of rotation spaced from the common axis of rotation of the elements, means to prevent the second member from rotating in one direction of rotation about its own axis of rotation, a gear carried by the second member functioning as means to establish and disrupt a driving connection between the elements, adapted to mesh with the first said gear, rotate about its own axis of rotation and rotate bodily about the axis of rotation of said second member and means controlled by the speed of one of the elements for locking said member against rotation about its own axis of rotation prior to a predetermined speed and subsequently of another predetermined I speed of said one of the elements.

'1. In a step-speed power transmission in combination, a speed-shifting mechanism having a driving element and a driven element rotatable about a common axis of rotation, a gear rotatively attached to one of the elements, an eccentric rotatively attached to the other element, a member mounted on and free to rotate a limited amount about the eccentric, a gear carried by said member functioning as a means to establish and disrupt the driving connection between the elements, meshing with the first said gear, rotatable about its own axis of rotation and bodily rotatable about the eccentric.

8. In a step-speed power transmission in combination, a speed-shifting mechanism having a driving element and a driven element rotatable about a common axis of rotation, a gear rotatively attached to one of the elements, an eccentric rotatively attached to the other element, a member mounted on and free to rotate a limited amount about the eccentric, a gear carried by said member functioning a a means to establish and disrupt the driving connection between the elements, meshing with the first said gear, rotatable about its own axis of rotation and bodily rotatable about the eccentric and means controlled by the speed of one of the elements for locking said member against rotation about the eccentric until a predetermined speed of said one of the elements is attained.

28 9. In a step-speed power transmission in combination, a speed-shifting mechanism having a driving element and a driven element rotatable about a common axis of rotation, a gear rotatively attached to one of the elements, an eccentric rotatively attached to the other element, a member mounted on and free to rotate a limited amount about the eccentric, a gear carried by said member functioning as a means to establish and disrupt the driving connection between the elements, meshing with the first said gear, rotatable about its own axis of rotation and bodily rotatable about the eccentric and means controlled by the speed of one of the elements for locking said member against rotation about the eccentric prior to a predetermined speed and subsequently of another predetermined speed of said one of the elements.

10. In a step-speed power transmission in combination, a speed-shifting mechanism having a driving and a driven element rotatable about a common axis of rotation, a gear rotatively attached to one of the elements, an eccentric loosely splined on the other element for limited rotational movement relative thereto, a member mounted on and free to rotate a limited amount about the eccentric, a gear carried by said member functioning as a means to establish and disrupt the driving connection between the elements, meshing with the first said gear, rotatable about its own axis of rotation and bodily rotatable about the eccentric and resilient driving connections between the said other element and said member adapted to rotate the member about the eccentric and to maintain in predetermined relative positions the said other element and said member when the driving connection between the elements is disrupted.

11. In a step-speed power transmission in combination, a speed-shifting mechanism having a driving and a driven element rotatable about a common axis of rotation, a gear rotatively attached to one of the elements, an eccentric loosely splined on the other element for limited rotational movement relative thereto, a member mounted on and free to rotate a limited amount about the eccentric, a gear carried by said member functioning as a means to establish and disrupt the driving connection between the elements, meshing with the first said gear, rotatable about its own axis of rotation and bodily rotatable about the eccentric, resilient driving connections between the said other element and said member adapted to rotate the member about the eccentric and to maintain in predetermined relative positions the said other element and said member when the driving connection between the elements is disrupted and means controlled by the speed of one of the elements for locking said member against rotation about the eccentric until a predetermined speed of said one of the elements is attained.

12. In a step-speed power transmission in combination, a speed-shifting mechanism having a driving element and a driven element rotatable about a common axis of rotation, a gear rotatively attached to one of the elements, an eccentric loosely splined on the other element for limited rotational movement thereto, a member mounted on and free to rotate a limited amount about the eccentric, a gear carried by said member functioning as a means to establish and disrupt the driving connection between the elements, meshing with the first said gear, rotatable about its own axis of rotation and bodily rotat- 

